


The Monster in Sam's Pants

by were_lemur



Category: Supernatural
Genre: Bottom Dean, M/M, Plot What Plot/Porn Without Plot, Switching
Language: English
Status: Completed
Published: 2017-12-26
Updated: 2017-12-26
Packaged: 2019-02-21 23:02:59
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,769
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13153872
Author URL: https://archiveofourown.org/users/were_lemur/pseuds/were_lemur
Summary: Dean wants Sam to fuck him, for a change.  Sam isn't sure that's a good idea.





	The Monster in Sam's Pants

It's not that Dean doesn't enjoy fucking Sam through the mattress; he loves watching is brother come completely undone, and knowing that he's the one who's done it to him. The sounds Sam makes when Dean rocks his cock in and out of him, the way he's so ready that Dean can't even touch his cock until he's at the edge himself, because two or three strokes is all it takes to push Sam over the edge.

It's just that Dean wants to feel the way Sam looks when he's splayed across the bed, blissed-out, fucked-out, completely satisfied.

So (once they've both caught their breath) Dean says "maybe next time you can fuck me instead?"

"Dude, I'd _kill_ you."

"You're not _that much_ bigger than me."

"It's not the length, it's the girth."

"You've fucked other people."

"All those other people have been _women_. You know, people who possess organs designed to accommodate a whole baby?"

"Are you trying to give me a _sex ed_ lesson?"

Sam lets out an annoyed huff. "I'm trying to prevent the world's most embarrassing ER visit."

"Yeah, well I think my ass can handle your monster dick."

"I can't believe we're even _having_ this conversation," Sam mutters. "Now go back to your own bed, so we can both get some sleep."

*

Once he's started thinking about it, though, he can't stop. And the frustrating thing is, though technically it wouldn't be impossible to get fucked in the ass without Sam, it would be a lot more difficult than it seemed on the surface.

He could, he supposed, go out and pick up some guy to do the deed. But somehow, sleeping with another man would feel like he was betraying Sam, in a way that none of the chicks he'd banged since they'd started their -- whatever the hell this was -- would.

Alternatively, he could try to get a woman to fuck him with a strap-on. He knows there are women out there who are into that, but it seems like an awfully awkward question to ask someone he's just met. And if the answer is no, he will have probably soured them for any more conventional bedroom fun. (Or kitchen countertop fun, or jacuzzi fun, or couch fun.)

He could buy himself a dildo, but even if he could handle the awkwardness of the actual purchase, he'd still have to worry about Sam finding it. That would just be too weird.

But he has hands, and technically speaking he only needed one to jerk off with. So the next time he has the room to himself for an hour for some real "me time" instead of a quick jerk-off in the shower, he lubes up a finger and slips it inside. He remembers how long it had taken to get Sam opened up the first time they'd decided to try actual penetration.

(Now Sam is a pro; Dean just slicks up and slides into his brother's tight heat like they were made for each other.)

It's definitely an odd sensation; Dean spreads his legs open wider and tries different angles, but there is no position that isn't awkward. Still, he gets used to it and slips a second finger in, and while it's nothing like the reaction he sees from Sam, when he jerks himself off and his muscles clench around this fingers, he comes harder than he has in a long time.

More and more often, when he's fantasizing or just daydreaming, he finds himself thinking of bending over while Sam fucks him in the ass. It doesn't completely replace his old reliables, but it's definitely in the regular rotation. And he keeps looking for opportunities to get an hour or two alone in the motel, so he can finger-fuck himself.

He works his way up to three fingers, and learns where to press them so that warmth spreads through him.

By the time a few months have passed since their conversation (they never talk about sex when they're not having it, and Sam doesn't seem to want it all that often) he suspects that Sam has forgotten all about it.

*

When they pull into a university town and Sam says he's going to spend a few hours at the library, it's just the opportunity Dean has been hoping for. He spreads a towel on the bed, and decides to try it on all fours, so he can imagine Sam has him bent over and is pounding him from behind.

He's most of the way there and considering trying to get a fourth finger in (and he thinks about getting a whole hand in there and that leads him directly to the thought that Sam has very large hands, and just that thought is almost enough to tip him over the edge) when the door swings open.

He's got his ass in the air and his fingers inside and for a moment, he freezes. Then he pulls his fingers out and staggers to his feet and toward the bathroom. "Don't you ever knock?"

Sam blocks his path.

"What are you even doing here?" Dean demands, trying to step around him.

"Power failure on campus. Dean. Stop."

"I need a shower."

"Let me watch?"

He'd been expecting ridicule, not -- 

Sam takes his hand, and presses it to the crotch of his own jeans. The monster is there, stirring into wakefulness.

"I want to watch," Sam says again, and then, his voice huskier, "Let me watch you finger-fuck yourself, Dean."

Embarrassment and lust have a brief internal battle. Lust wins. Maybe even if he can't get Sam to fuck him in the ass, at least he'll get some dirty talk out of it.

He's nervous as he climbs back on the bed, but he slicks his fingers again. Presses them inside. Begins to thrust, and even though he doesn't have the angle to get much penetration with each stroke, it's something.

His other hand strokes his cock, just lightly. He doesn't want to end this too soon.

Sam is still fully clothed, just rubbing himself through layers of denim and cotton.

"Why don't you pull it out, Sam? Let me see it, even if you won't let me have it."

Sam unzips and pulls his cock out over the top of his briefs. "This is what you want?"

"Yes." It's very nearly a groan. "I've been thinking about that giant cock of yours for weeks. Months. Every time I shove my fingers in, I'm imagining you fucking me." He's moving his fingers in easily now. "You think I could take another finger, Sam?"

"I think," Sam says at last, "That you can take more than fingers."

He undresses slowly, folds his clothes on his own bed. Then he kneels behind Dean, and his fingers slide over Dean's hips. He pulls Dean's hand away, leaving him utterly exposed.

"Kneel up," he says, and Dean does.

"You remember how the first time you fucked me, you let me ease down on you, inch by inch, until I had all of you inside me?"

It's not what Dean pictured; he wants Sam to bend him over and fuck him through the mattress. But if this is the way Sam wants to do it, he'll be happy just getting fucked.

He hears Sam tearing open the rubber, and then he grabs the lube, and then scoots forward so that he is kneeling behind Dean, between his knees. He tugs Dean gently back and then there's the head of Sam's cock, pressed against his entrance.

"Take your time," Sam says, and Dean presses back. He means to take it all in one, smooth stroke, but it definitely feels bigger than it looks. It pinches, going in, and Dean slows for a moment to adjust. He hears a whimper from Sam, feels Sam's hands clench on his hips, as if he's fighting the urge to grab Dean and pull him down hard or hold him still and pound in him.

Dean presses himself down again and breathes, and that first slow thrust seems to go on and on but finally he feels his hips pressed against Sam's stomach. He's taken it all, and he feels oddly accomplished.

He presses himself up halfway, and then lowers himself back. Does it again, faster this time, and his cock, which had gone to half-mast during the proceedings, starts to perk up again.

It feels good, but not as good as when his fingers had pressed over that one spot. "The angle's not quite right."

"Try leaning forward?"

He does, and presses his hands onto the bed. Sam shifts as well, and this time at least there's some contact. "Better, but not quite right."

"Do you want to try rolling over?"

He's got Sam's cock in him all the way, but somehow, the idea of Sam watching his face as he gets fucked feels like too much. Instead, he leans further forward, rests his weight on his arms, presses his forehead against the sheets.

It's like playing the world's porniest game of hot-and-cold, as Sam tries different angles and Dean tells him whether it feels better or worse. When Sam finally finds the best one, though, Dean can't make any words at all.

"Good?" Sam asked.

Dean nodded, and Sam began to thrust slowly, rolling his hips.

"More!" 

Sam snaps his hips forward, and Dean bucks back to meet him. He lets out a low, desperate groan, and his fists clench in the cheap motel sheets. Closer, closer to the edge, and he realizes that there's a serious disadvantage to this position; Sam won't be able to jerk him off without changing the angle, and that means that he's going to have to do it himself, but he doesn't know how close Sam is, and he can't really find the words or the breath to ask them and -- 

Every muscle in his body clenches, he hears his own voice muttering _oh fuck oh god oh Jesus Sammy fuck yes so good_ but he's not really saying the words and then Sam cries out too, and slams into him, changing the angle, shoving him down against the mattress but he's too far gone to care.

He comes back to himself, pressed into the mattress. Sam is still shuddering with aftershocks, and he combs his fingers through Dean's hair. It's more tenderness than either of them would allow outside of these moments.

Since it's his bed, he should be telling Sam to move. Instead, he lets his eyes fall closed. If he's very lucky, he thinks, he'll be asleep before Sam's cock slips out of him.


End file.
